Conventionally, a battery module in which a plurality of electricity storage devices that each have positive and negative electrode terminals are arranged side-by-side is used as a battery module for electric vehicles and hybrid vehicles. As an example of such a battery module, there is a well-known battery module in which positive and negative electrode terminals are connected to each other by a bus bar, and thus a plurality of electricity storage devices are electrically connected to each other. To electrically connect a plurality of electricity storage devices to each other, a wiring module such as that shown in Patent Document 1 (JP 2013-97962A) is used.